Resister.



P. KRAEUTER & S. M. KINTNER.

RBSISTER.

urmouxon FILED nnq.1o. 1910.

1,068,907. Patented July 29, 1913.1

AVAVAVAVAVAVAVAVA A AVA a A A A A A A A A AVA AVAVA A A AVZ 3 Q Q Q Q G Q WITNESSES: INVENTORS UNITED STATES PATENT OFFICE.

PAUL KRAEUTER, OF WILKINSBURG, AND SAMUEL M. KINTNER, OF PITTSBURGH, PENNSYLVANIA, ASSIGNORS TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

RESIST-ER.

Specification of Letters Patent.

Patented July 29, 1913.

Application filed December 10, 1910. Serial No. 596,645.

To all whom it may concern Be it known that we, PAUL KRAEU'I'ER and SAMUEL M. KINTNER, citizens of the United States, and residents, respectively, of Wilbar or strap resister of such cross sectional area and shape as to have suflicientmechant.

cal strength to withstand all ordinary strains to which it may be subjected and be pos sessedof thelfequisite degree of resistance, and also be so constructed that it will not.

injure its inclosing insulation duringthe ap plication of such insulation or during other manipulations. The conductor is also of such form that its resistance may be localized, as desired, without materially weakening it.

The armature windings of commutatortype single-phase motors are usually connected to the commutator segments by means of resistance leads that are usually located in the same core slots as the windings. such conductors are of suflicient cross-sectional area to have the necessary strength, their resistances are usually too low, and, it has accordingly been proposed to locally increase the resistances of the conductors where they are embedded in and supported by the armature core, and where, consequently, a lesser degree of strength is necessary. The embedded portions of the conductors are also better able to withstand large currents without overheating, because heat is conducted from them by the surrounding parts.

According to our present invention, a resister is provided in which the resistance is locally increased, and which has continuous edges, so that there is little or no liability of injuring the insulation during its application thereto or during the placing of the resister in the armature slots.

Figure l of the accompanying drawing is a sectional view of one half of the armature of a dynamo-electric machine in which a resistance conductor is employed that is constructed in accordance with the present in vention. Fig. 2 is an enlarged side view of the resistance conductor shown in Fig. 1, and Fig. 3 is a similar view of a modified form of resistance conductor.

The armature of Fig. 1 comprises a laminated core portion 1, having longitudinal slots in its outer peripheral face, in which are located an armature winding 2 and resistance leads 3 that connect the armature winding to the commutator segments 4.

The resistance leads 3 are preferably in the .form of straps or ribbons, and, in order that the end portions thereof, which are unsupported, may have sufiicient mechanical strength to withstand the strains incident to the operation of the machine, and sufiicient thermal capacity to withstand mom entary overloads, the cross sectional area thereof'is imade, larger than is necessary to give the straps the proper degree of resistance. However, the resistances of the portions of the straps that are located within the core slots, and are thus supported by the armature core, are increased, preferably by pro-.

viding the same with triangular apertures that are alternately disposed nearer one edge of the strap than the other, the bases of the triangular apertures being parallel to the lateral edges of the straps. A main zigzag path for current is thus provided in the resistance conductors while auxiliary paths extend between the vertices of themain path. The resistances of the main and auxiliary paths are so proportioned, with respect to each other, that the main portion of the current will traverse the main path, and also so that the currents which traverse the auxiliary paths will not overheat the same or will not heat them to a much greater degree than the main path is heated by the passage of current through it. When thus constructed, the resistance lead has a continuous edge, while, at the same time, its resistance is locally increased.

Since the lateral edges of the lead are continuous, there is no liability of cutting or otherwise injuring its insulation by twisting or bending the lead, and the lead is stronger than if it were merely provided with slits extending inwardly from its lateral edges. The portions of the leads that are located in the armature slots are supported by the armature core, so that it is not necessary that they should possess as great strength as the unsupported end portions thereof, and, by reason of their engagement with other parts, heat is more readily conveyed away from them than from the end portions which do not engage other parts. The leads, therefore, become heated to a substantially uniform degree throughout their lengths.

The apertures in the resistance conductors may also be circular inform, as shown in Fig. 3, or-t-hey may be of other shapes, if desired, without departing from the spirit of our invention.

We claim as our invention:

1. A resister having a intermediate portion provided with apertures that are alternately disposed nearer to one edge thereof than to the other.

. 2. A resister consisting of a strap having continuous edges and a zig-za-g formation in a single plane between said edges.

3. A resister consisting of a strap having apertures alternately disposed nearer to one edge thereof than to the other.

4. A resister consisting of a strap having and relatively high-resistance paths between the vertices of the zigzag path.

A resister consistingof a strap having a. main transversely extending ath of low resistance and relatively hig h-resistance paths extending longitudinally between parts of the low-resistance path.

6. A resister consisting of a strap having a main path of zig-zag form and relatively large cross-section and auxiliary paths of less cross section between the vertices of the zig-zag path.

In testimony whereof, I have hereunto "subscribed my name this 1st day of December 1910.

. PAUL KRAEUTER. Witnesses:

' W. H. BELL,

C. A. GooDwrN.

In testimony whereof, I have hereunto subscribed my name this 8th day of December 1910. SAML. M. KINTNER.

Witnesses:

JNo. S. DEAN,

a main low-resistance path of zig-zag form Copies of this patent may be obtained for five cents BwB. HINES.

each, by addressing the Commissioner of Patents Washington, D. C. 

